Tests On The Behavior Of High-Strength Concrete Beam-Column Connections

For economy and ease of construction , multistory buildings often use a lower concrete strength for the beam-slab system than for the columns . For further convenience , the beam-slab system concrete is often made continuous though the column .While the variation in concrete strength is too large ,the capacity of the connection is lower than that of the column . Thus, in order to improve the capacity, the connection must be strengthened. The paper describes the results of tests of 5 reinforced concrete beam-column interior connections specimens, in which the columns are very strong concrete while the intervening beams are much weaker . The paper describes the difference of the capacity between the connections and the columns and investigates the capacity of the connections when they are strengthened by the shapes . The paper also investigates whether the corresponding provisions of the current code are economical and safe. A formula is suggested according to the results . In addition , the shapes can retard the development of cracks and improve the shearing strength according to the results .